Income Taxes Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The following table presents the provision for income taxes and the effective tax rates for the three months ended March 31, 2018 and 2017:

	Three Months Ended March 31,
(Dollars in thousands)	2018			2017
Income before income tax expense	$	81,173		$	72,992
Income tax expense	17,552			22,519
Effective tax rate	21.6		%	30.9		%